An image sensor that captures a subject image and outputs an image signal includes pixels. When strong light with intensity more than a certain level enters a pixel, an output signal from the pixel is saturated. Since signal values from all the saturated pixels are treated simply as being at a saturated level, the obtained image is observed as a so-called overexposed image. To avoid such saturation in a pixel, there is disclosed in Patent Document 1 a technology of providing groups of light-receiving elements having different imaging sensitivities in combination, so that when output signals from a group of light-receiving elements having a higher imaging sensitivity are saturated, output signals from a group of light-receiving elements having a lower imaging sensitivity can be used, thus preventing the occurrence of overexposed images.
Patent Document 1: Japanese Laid-open Patent Publication No. 2000-125209